title: Iterative image reconstruction for ultra-low-dose CT with a combined low-mAs and sparse-view protocol.
abstract: Ultra-low-dose x-ray computed tomography (CT) imaging is needed in CT fields. Through a scan protocol by lowering the milliampere-seconds (mAs) and reducing the number of projections per rotation around the body, we can realize low-dose CT imaging. However, the resulting noisy and insufficient measurements will unavoidably cause the degradation of desired-image. To solve this problem, iterative image reconstruction is a promising choice for achieving high-quality image with a low-dose scan. In this study, we are focusing on ultra-low-dose CT image reconstruction by using penalized weighted least-square (PWLS) criteria with a combined low-mAs and sparse-view protocol. Specifically, the sinogram data acquired with a combined low-mAs and sparse-view protocol is first restored by using a PWLS based sinogram restoration method. Then, the restored sinogram data is hereafter used to reconstruct image by using a PWLS based total variation (PWLS-TV) method. Qualitative and quantitative evaluations by simulations were carried out to validate the present method.
authors.forename: Yunwan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Huang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Ma
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Zhaoying
authors.initials: Z
authors.lastname: Bian
authors.forename: Dong
authors.initials: D
authors.lastname: Zeng
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.forename: Wufan
authors.initials: W
authors.lastname: Chen
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004307:Dose-Response Relationship, Radiation; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D016018:Least-Squares Analysis; D019047:Phantoms, Imaging; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*